fix(desktop): say why local files are out of reach, and drop non-null assertions in tests

When the app has no usable account storage (signing out, switching
account, storage unavailable), a local file call now says so. It no longer
tells the model a setting is off and to ask the user to switch it on.

Author: waleedlatif1

apps/desktop/src/main/desktop-executor/executor.test.ts

@@ -22,8 +22,8 @@ interface Deferred<T> {
 }
 
 function deferred<T>(): Deferred<T> {
-  let resolve!: (value: T) => void
-  let reject!: (error: unknown) => void
+  let resolve: (value: T) => void = () => {}
+  let reject: (error: unknown) => void = () => {}
   const promise = new Promise<T>((res, rej) => {
     resolve = res
     reject = rej

apps/desktop/src/main/desktop-executor/runner.test.ts

@@ -1,7 +1,7 @@
 import type { TerminalToolResponse } from '@sim/terminal-protocol'
 import { afterEach, describe, expect, it, vi } from 'vitest'
 import type { ClaimedDesktopCall } from '@/main/desktop-executor/protocol'
-import { createDesktopToolRunner } from '@/main/desktop-executor/runner'
+import { createDesktopToolRunner, type DesktopToolRunnerDeps } from '@/main/desktop-executor/runner'
 
 function terminalCall(toolCallId: string, operation: string): ClaimedDesktopCall {
   return {
@@ -14,7 +14,7 @@ function terminalCall(toolCallId: string, operation: string): ClaimedDesktopCall
   }
 }
 
-function runnerWithTerminal(executeTool: (toolCallId: string) => Promise<TerminalToolResponse>) {
+function runner(overrides: Partial<DesktopToolRunnerDeps> = {}) {
   return createDesktopToolRunner({
     preferences: () => ({ browserEnabled: true, terminalEnabled: true }),
     accountDataAvailable: () => true,
@@ -24,12 +24,19 @@ function runnerWithTerminal(executeTool: (toolCallId: string) => Promise<Termina
       hasSession: () => true,
       restoreScope: vi.fn(),
     },
+    terminal: { executeTool: vi.fn(), cancelTool: vi.fn(async () => true) },
+    localFiles: { read: vi.fn() },
+    localFilesystem: { handle: vi.fn(), vfsRoot: () => 'user-local/x--1' },
+    ...overrides,
+  })
+}
+
+function runnerWithTerminal(executeTool: (toolCallId: string) => Promise<TerminalToolResponse>) {
+  return runner({
     terminal: {
       executeTool: (_scope, toolCallId) => executeTool(toolCallId),
       cancelTool: vi.fn(async () => true),
     },
-    localFiles: { read: vi.fn() },
-    localFilesystem: { handle: vi.fn(), vfsRoot: () => 'user-local/x--1' },
   })
 }
 
@@ -94,3 +101,23 @@ describe('background terminal calls', () => {
     expect(started).toEqual(['wedged'])
   })
 })
+
+describe('local file calls', () => {
+  it('names a passing storage state, not a setting, when local files are out of reach', async () => {
+    const completion = await runner({ accountDataAvailable: () => false }).run(
+      {
+        toolCallId: 'read-1',
+        toolName: 'read_local_file',
+        args: { path: '~/notes.txt' },
+        chatId: 'chat-b',
+        workspaceId: 'ws-1',
+        executionToken: 'token-read-1',
+      },
+      new AbortController().signal
+    )
+
+    expect(completion.data).toMatchObject({ notStarted: true })
+    expect(completion.message).toContain('cannot reach local files')
+    expect(completion.message).not.toContain('settings')
+  })
+})

apps/desktop/src/main/desktop-executor/runner.ts

@@ -51,6 +51,13 @@ function surfaceOff(surface: string): DesktopToolCompletion {
   return { status: 'error', message, data: { error: message, notStarted: true } }
 }
 
+/** Local files are out of reach while the app has no usable account storage, a passing state. */
+function localAccessUnavailable(): DesktopToolCompletion {
+  const message =
+    'Not run: this action never started, because the Sim desktop app cannot reach local files right now (it is signing out, switching account, or its storage is unavailable). Nothing happened on the user’s computer. Do not retry it in this turn; tell the user, who can ask again once the app is ready.'
+  return { status: 'error', message, data: { error: message, notStarted: true } }
+}
+
 function unsupported(toolName: string): DesktopToolCompletion {
   const message = `Not run: this action never started, because this version of the Sim desktop app cannot run ${toolName} in the background. Nothing happened on the user’s computer. Do not retry it in this turn; tell the user to update the Sim desktop app.`
   return { status: 'error', message, data: { error: message, notStarted: true } }
@@ -222,7 +229,7 @@ export function createDesktopToolRunner(deps: DesktopToolRunnerDeps): DesktopToo
       try {
         if (isCurrentBrowserToolName(call.toolName)) return await runBrowser(call, call.toolName)
         if (call.toolName === 'terminal') return await runTerminal(call, signal)
-        if (!deps.accountDataAvailable()) return surfaceOff('local file access')
+        if (!deps.accountDataAvailable()) return localAccessUnavailable()
         if (call.toolName === 'read_local_file') {
           return localFileReadCompletion(await deps.localFiles.read(call))
         }